The Royal Courts of Justice. Photograph: Graham Turner for the Guardian

Maidenhead might, until this week, have claimed to be the divorce capital of Italy. One hundred and eighty Italian couples whose marriages were dissolved through fictitious residence in the Berkshire town have now had their divorces annulled by a British judge.

The conspiracy to circumvent the slow-moving Italian judicial system was formally ended on Tuesday by the president of the family division of the high court, Sir James Munby.

In a lengthy judgment (pdf) that detailed the bizarre fraud, the judge explained how English and Welsh courts were inundated with divorce petitions from Italian couples claiming that at least one partner was living in the UK.

For the price of around €4,000, a woman calling herself Dr Frederica Russo arranged to provide divorce papers for couples who wished to separate. Large numbers of county courts were used in order to spread the workload and avoid anyone noticing the repeated use of the same address.

“The problem was first identified in late February 2012 by an eagle-eyed member of the court staff at Burnley county court, Julie Farrah, who spotted that in two files, both involving Italian parties, the address was the same and that it was in Maidenhead,” Munby said.

“She brought it to the attention of district judge Conway, who contacted a colleague in the Slough county court. He arranged for a member of the court staff there to visit Flat 201, [5 High Street, Maidenhead] which revealed that there was no residential accommodation there.”

County courts were alerted and eventually 179 petitions using the same address were discovered; one Italian husband and wife, using the same method, had preferred to end their relationship through an address in Epsom.

“It is certain that none of them can ever have resided at Flat 201,” Munby added. “On 28 August 2012, police officers of the Thames Valley police executed a search warrant. DS Steven Witts of Thames Valley police confirms that Flat 201 was not a residential property or, indeed, a property capable of occupation.

“It was in fact a mailbox, mailbox 201, one of a number of mailboxes located in commercial premises. As the investigating officer in charge of the police investigation, DS Jonathan Groenen, mordantly commented in his witness statement: ‘It is not possible for 179 applicants or respondents to reside at this address.’ Indeed, given the dimensions of the mailbox it is clear that not even a single individual, however small, could possibly reside in it.”

The divorces were illegal, Munby said, because the English courts were being deceived about their jurisdiction. The divorces therefore had to be declared void through fraud even “if one or other or both of the parties have remarried or even had a child”.

The case will inevitably reinforce national stereotypes: while Hollywood film stars celebrate their nuptials in Venice, Italians choose Britain as a passion-killer.